Britain's immigration map tells us much about the country's social and political history - something clearly seen with the American-born population.

The largest single local cluster is Mildenhall in Suffolk – the site of one of the largest US Air Force bases in the world, a legacy of the Cold War and Nato co-operation. Beyond that, London is home to many Americans, mostly workers in the City of London.

This population is anecdotally thought to be fairly mobile, coming for a few years or just perhaps a few months before departing again.

Some of the Americans showing in the figures will be older, ex-servicemen who returned after being based in Britain during World War II.

Concentrations of people born in the USA

Map on right shows country as if areas with roughly equal populations were the same size. So, densely populated London takes up much more space than sparsely populated Scottish Highlands.

At-a-glance

155,030 people born in the US were living in Britain in 2001, up almost 8% on 1991 and representing about 0.01% of the total population.

36% of US-born in Britain live in London – generally reflecting the strong financial and political ties between the capital and New York and Washington.

20% fewer US-born people lived in the East of England than in 1991, reflecting the post-Cold War reduction in airbases there.

6 areas close to military bases saw steep declines in their US-born populations but six areas in London saw steep increases.